Inner tube



May 1, 1923. i,453,949

H. C. PRIVETT INNER TUBE Filed April ll, 1921A LAUDE PRIVETT, OF LONG BEACH, CALIFORNIA, .ASSIGNOR F ONE-HALF TO =c` 5I' ES R. PRN ETT, OF BURBANK, CALIFORNIA, THREE-SJIXTEENTHS '1'.0 I E. PRIVETT AND ONE-SIXTEENTH TO HOLLIS F. IE'IRIVJE.'J.'.lJ,l BOTH OF LONG BEACH,

:Sii EN INNER TUBE.

Application led April ll, 1921. Serial Elo. ,369.

To all whom it may concern.

BeA it known that I, HENRY CLAUDE PRIvmT, a citizen of the United States, residing at Long Beach, in the county of Los Angeles and State of California, have invented newand useful Im rovement-s in lnner Tubes, of which the following is a speciication.

It is the objectof thisinvention to pro- 10. vide an inner tube for pneumatic tires, of

the type which is so constructed as to substantially anchor the side edges of the inner .portion ofthe tread of the tube against l transverse expansion when the tube is in- Hated, so asto compress said portion of the tread and thereb' provide for the immediate closing or sea ingb any ordinary puncture that may occur.

In the present invention the anchoring of the side edges of the inner portion of the tread of the tube a ainst transverse expansion is accomplish by means of transversely extending nonexpansible members embedded in the tread of the tube, and arranged alongside of one another around the entire periphery of the tube. By such aconstruction, while said nonexpansible members positively anchor the side edges of the inner portion of the tread of the tube against expansion, for the purposeset forth, said nonexpansible. members through their spaced relation alongside one another around the periphery of the tube, will. permit of the necessary radial and circumferentlal expansion of the tube when it is inflated.

' The provision of the anchoring means, as thus described, also eliminates meeting edges between the tube stock and the anchorin means, and as a consequence I have'elimi- 40 nated the possibility of the tube stock pulling away from the anchoring means, as 1s liable to occur when a fabric strip anchoring means, extending around the Yperiphery of the tube, lis employed.

,45 The provision of transversely extending anchoring members positioned alongside of one another with slight circumferential spaces between the same, also permits of the tube stock being received between said anchoring elements and completely around .the same, so as to entirely embed the anchoring elements within the tube stock, and thereby still further prevent the possibility of said tube.

.to compress,

anchoring means pulling away from the 4The improved construction also contemplates the provision ofla circumferentially extending stri of relatively hard tube stock embedded wit in the tube which is of relatively soft stock, this strip being positioned between the inner and outer surfaces of the tread of the tube so as to assist, 'through its relatively slight transverse expansion when the tube is inflated, in the anchoring of the side edges of the inner portion ofthe tread of the tube against transverse expansion, as previously described, and for the purpose Aset forth.'

If desired the inner portion of the tread of the tire which is adapted to be held against expansion and compressed, as above described, may be of a' relatively mmy plastic material instead of the usua relatively soft tube stock forming thetube, inv order that said inner portion of the tread of the' tube will tend,'through the sticky composition of the same, to fill and seal any, punctures which may occur in the tube. It will thus be seen that not only the tendency of the inner portion of the tread of the tube but also the peculiar composition of said portion of the'tread of the tube, will cause closing and sealing of any punctures which ymight occur, and as a consequence an extremely eicient tire tube is pro'- vided. y v

4 The invention will be readily understood from the following description of the accompanying drawings, in which Figure l' is a transverse section through an inner tube constructed in accordance with the invention, and showing the same turned inside out as it is formed upon a mandrel. A

Fig. 2 is a longitudinal section on the line 2 2 0f Fig. 1.

Fig. 3 is a plan view of a portion of the inner tube when turned inside out.

Fig. 4 is a similar view showingthe tube partly broken away to showlthe anchoring 100 cords embedded therein.

Fig. 5 is a transverse section through a typical tire casing having an inner tube, constructed in accordance with the present condition.,

Fig. o is a similar view showing the inner tube initiated.

ln the drawings, l have illustrated a usual tire casing l mounted' upon a rim 2, the illustration ol these arts representing simply a typical construction and not being intend theinner tube forming the sub-A ed to limit ject'matter ot the present invention to any particular type oit tire casing.

The inner tube, as in the usual practice, is constructed upon a mandrel inside out, and the arrangement of the inner tube as thus positioned and as illustrated in Fig. l will hrst be describedB The oundation of the inner tube is shown at 3 as a tube of usual inner tube stock which is relatively soit rubbera A circumferential strip l is suitably secured to the tread portion ol the tube Stoch and extends transversely thereof throughout the entire tread portion oi the tube. This strip is ot relatively hard rubber, such as the stock generall employed for the outer surface of the usua tirecasing. The strip t is arranged so that its cross sectional configuration is as shown in Fig. l, with the middle ortion of the strip comparatively thiol; ancltapering toward its side edges. As will be readily noted the strip is curved in cross section so as to conform to the cross sectional curvature ot the tube stocln ylChe outer tread strip 5 is received against prises a plurality v edges o-strip d,

strip lso as to entend around the tube. This strip preferably extends transversely of the tube somewhat beyond the ends ol strip 4, as clearly shown in Fig. l, and is curved to contorni to said tube with its middle portion relatively thiclr and its side edges tapering away at their junction with the tube stools 3. This strip, which is the pore tion ot the tube which is compressed when the tube is initiated, is preferably of a somewhat sticlry plastic composition which is relatively sott so as to be readily compressed and which will tend to positively seal a puncture in the tube, due to its sticky composition, as well as the compression under which it is maintained when the tube is inflated.

Anchoring means are provided between strips land 5 and are embedded in said strips, it being understood that the nished tube has the various portions thereof firmly united so as to form a substantially integral structure, as by vulcanizing, or any other suitable process. The anchoring means comol cords 6 extending transversely oil the tube and spaced circumferentially one beyond another, rlhese cords eX- tend across the tread portion ol the tube and preferably terminate short of the side as clearly shown in llig. l.

Alt will be noted that by embedding the cords in the tube structure and at the same 4time dircumterentially spacing the same, that said cords will be completely surroundinsana@ ed by the material ormin the'tube and will thus be firmly embed ed against displacement. lt will also be noted that the employment ol cords as the anchoring means, does awaywith the meeting edges between the anchoring means and the tube structure, so that there is no possibility of the tube cracking or splitting by the anchoring .means pulling away from the same. The cords forming the anchoring means being ol relatively inexpansible material, will thus provide means lor positively anchoring the side edges oia the tube relative to one another while permitting oi the necessary radial and circumferential expansion of the tube when the latter is inflated.

rllhe tube having been formed as thus described, it is removed from the mandrel and turned inside out in the usual manner, and the ends ot the tube are then sealed together to form the linished annular tube, such as is shown in transverse section in Figs. 5 and 6.

As illustrated in Fig; 5, when the tube is placed in the tire casing and is in its deilated condition, the tread of the tube will be oi uniform density throughout. lt will be noted that the inner portion 5 of the tube is so positioned that less extent than when the tube is inflated, and it will be further observed that the anchoring cords t3 maintain the side portions of the tube stock in fixed relation to the por-V tion 5 of the tube, so that when the tube is vinilatedto the position shown in Fig. 6, the

inner port-ion 5 of the tube is held against transverse expansion and must .therefore compress as it is forced radially outwardly to conform to the tire casing.

This inflation of the tube also causes the inner portion oi the tread to materially` decrease in area, and as a consequence the compression ol the inner portion 5 of the tube is accompanied by an increase in density thereof. As a result the compressed gummy stock 5 will tend to close any puncturc which may occur in the tube. and since this portion of the tube is under lateral compression, it wil] oder considerable resistance to any article tending to puncture the tube. provision of relatively hard strip Ll will tend to prevent puncturing of the tube, and through its relative nonexpansion with relation tothe readily expandible and compressible stock 5 will assist in the .compression of the inner portion of the tread of the tube as above set forth.

ln the event of a puncture in the tube, the withdrawalv of the puncturing object will not leave an 'opening inthe tube, since the sticky material 'forming the inner portion of the tread of the tube will immediately close 'and tightly seal the opening,

dueto both its.' compressive action and the its inner surface is ot llo lill@ lt will be further noted that the sticky plastic material of which it is formed. It will thus be seen that I have provided an inner tube structure wherein the" provision of anchoring. means in the tread of the tube will cause compression of the inner portion of the tube so as to quickly close any puncture that may occur, said sealing of a puncture being further accomplished by the plastic sticky composition of t-he inner portion of the tread of the tube.

The arrangement of the anchoring means as circumferentially spaced transversely eX- tending cords also provides means for posi- .tively embedding said anchoring means so as to prevent pulling away of the same from the tube structure, and such an arrangement also permits of the radial and circumferential expansion of the tube, while maintaining the same against transverse expansion so as to produce a desiredv compressive action in the inner portion of the tread of the tube.

Various changes may be made without departing from the spirit of the invention as claimed.

What is claimed is:

1. An inner tube for tires comprising anannular strip of substantially inelastic material arranged in the tread portion of the tube between the inner. and outer surfaces thereof, and inelastic anchoring members arranged transversely at intervals within the tread portion and at the inner side of vthe tube is infiated.

3. An inner'tube for tires comprising a compressible strip on the inner side of the tread portion, inelastic anchoring members arranged transversely `at intervals within the tread portion and' operating to effect compression of the strip 'when the tube is inflated, and a strip of relatively hard rubber interposed between the outer surface of the tread and the inelastic members so that v its edges extend'v beyond the ends of the members. v l

4. An innertube for tires having inelastic members arranged transversely of and embedded within the tread portion of the tube, and inelastic material embedded in theftread portion and associated with the members to prevent the tearing away of the terminals of the members when the tube is iniated.

In testimony whereof I have signed my name to this specication.

HENRY CLAUDE PRIVETT. 

